Distillation of hydrocarbons



April 1, 1930. H. H. HEWETSON DISTILLATION OF HYDROCARBONS Filed June25.

Cinema,

Patented Apr. 1, 1930 UNITED *s'rATEs PATENT OFFICE HENRY H. HEWETSON,OF ELIZABETH, NEW JERSEY, ASSIGNOR TO STANDARD OIL DEVELOPMENT COMPANY,OF NEW YORK, N. Y., A CORPORATION .OF DELAWARE DISTIDLATION OF I-IYDROCAR-BONS Application filed June 25,

Thisinvention relates to the art of tractiona1 distillation ofhydrocarbons of the character of petroleum, and will be fully understoodfrom the following description, taken in connection with theaccompanying drawing,

which represents a side elevation, somewhat the fractionating towers areof suitable construction to afford contact between vapors and.

liquid, containing transverse partitions 17 having openings for passageof vapors. Pref erably bell cap vapor distributors are located over theopenings and overflow tubes pro-, vided, although in' simpler formstamped perforated plates or woven wire fabric may be used. From thebottom of each tower of the battery a pipe connects into theintermediate region of the next tower, this-being illustrated by pipe 18from the tower ahead (not shown) to the tower 13, and the pipe 19 fromthe bot tom of tower 13 to the intermediate region of tower 14:. In eachconnecting pipe a pumping or lifting device is provided, preferably asteam lift 20, although in its broader aspects the inventionconten'iplates any fluid. lift or jet. device or even a mechanical pump,although the latter is much less satisfactory for handling hot oil. Fromthe bottom of the. tower 14 a connection 21 leads to a finalfractionatopening into the intermediate zone and at the lowest plate,and valves being provided to direct the feed as desired. From the bottomof the tower 22 a discharge pipe 25 leads through acooler 26 to a tank27, and from the top a vapor pipe 28 leads through a condenser 29 to areceiver '30. A vacuum pump 31 is COIIIIBCtBdSOjLS to apply a vacuum inthe final fractionating tower 22.

From the bottom line of tower 14; avalved ranged in a series, the stills11 and 12 repre-Q' ing tower 22, branches 23 and 24 respectively 1923.Serial N0. 647,515.

pipe 32 is arranged, to enable return of liquid "to the stills, whendesired, and the flow lines 33 are provided to allow the residuum whichis unvaporized to flow from still to still. A

pipeBI-B is provided to conduct residual oil from still 12 tothe tower22, but if desired the residue maybe run "to storage (not shown) bybranch pipe 33 Assuming the battery in operation, oil suitably preheatedis introduced into the lowest temperature stills, the temperatures beingmaintained progressively higher from still to qstil-lfrom't'lie lightend to the heavy end of the battery. Vapors correspondingly are takenoff by the successive stills, the llquid condensed in the towers isforwarded by the steam lift to thetower next in the series, and

the heavy residuum flows from still to still in I A the usual manner. Bythe time tower 1 1 is reached the lighter constituents have been takenoil in succession as naphtha, water white. gas oil, parall'indistillate. etc and' the bottom temperature is now usually as high as isfeasible short of crackingf The condensate from tower lat is then passedthrough pipe 21 to the final fractionating tower and by applying avacuum a further yield of heavy lubrieating distillatecan be taken offas vapors I through pipe 28 and condenser 29, and the.

bottoms are run ofl? through pipe 25 and coolor 26. Residual liquid fromstill 12 may also be conducted to tower 22 by line 33*. I am thus ableto secure very completeyields of lubricating stocks and all productswithout the operating difficulties of the old vacuum battery, and sharpseparation of all products besides.

\Vhile I have set forth the invention by reference to certain specificdetails, it will be understood that this is for the purpose ofillustration to make the invention clear, and that changes may be madewhich come within the spirit and scope of the invention.

lVhat I claim is: v 1. Apparatus ot' the character described,

which comprises stills in series, a fractionating tower for each still,pipes connecting in w succession from the bottom of one tower to nectingpipe for transferring liquid from one tower to the next tower,additional final fractionating means comprising a tower-operating solelyby the contained heat of the liquid flowing thereto, a pipe connectingfrom the bottom of the preceding fractionating tower to the intermediateregion of the lower part of said final fractionating means, and meansfor communicating a vacuum to said final fractionating means.

2. Apparatus of the character described, which comprises stills inseries, a fractionating tower for each still, pipes connecting insuccession from tower to tower, a fluid lift in each connecting pipe,final fractionating uneans operating solely by the contained heat of theliquid therein, a connection from the bottom of the precedingfractionating tower to said final fractionating means, and means forcommunicating a vacuum to said final fractionating means.

3. Apparatus of the character described, which comprises stills inseries, a fractionat- .ing tower for each still, pipes connecting in'succession from tower to tower, final fractionatmg means operatingsolely by the contained heat of the liquid therein and means by whichthe liquid condensed in the last tower and the residuum from the laststill may be introduced separately into the said final fractionatingmeans.

4. Apparatus of the character described, comprising stills in series, afractionating tower for each still, and means for transmitting theliquid condensed in each tower to the intermediate region of the towernext in series unmixed with the still residuum.

5. Apparatus of the character described, comprising stills in series, afractionating tower for each still, pipes connecting the bottom of eachtower to the intermediate region of the next tower, fluid lift means ineach connecting pipe and a flow line from each still to the nextsucceeding still.

6. Process for distillation of hydrocarbon oils, comprising flowing anoil through a series of distilling zones, passing vapor from each zoneto a corresponding rectification zone wherein liquid and vapor fractionsare produced, pasing the liquid fractions to the next rectification zoneand rectifying the liquid therein.

7. Process according to claim 6, in which liquid from the finalrectification zone as specified therein is further rectified in a finalrectification zone under vacuum, solely by means of the contained heat.

8. Process according to claim .6, in which residual liquid'together withliquid from the final rectification zone as specified therein, isfurther rectified in a final rectification zone under vacuum, solely byself-contained heat.

HENRY H. HEVVETSON.

